This invention relates to projection devices, such as photograhic enlargers and cameras and the like, and more particularly to a lens mounting and alignment apparatus wherein the pitch and roll of the lens stage may be selectively adjusted to achieve a necessary or desirable optical alignment of a lens element therein with respect to the camera center, a photographic object, the optical axis of the enlarger, a transparency, or the base upon which the image is to be focused.
In some photographic applications it is common to provide a vertical support structure which permits adjustable positioning therealong of a photograhic apparatus. For example, an overhead enlarger with a light source may be vertically positioned over photosensitive printing paper to project a light image thereon. In order to obtain both image clarity and high resolution, it is necessary that the lens element be positioned for optimum alignment with respect to the image bearing medium and the surface upon which the image is projected. Additionally, in some photographic applications, it is desirable to adjust the position of the lens element to coincide with camera inclinations or to create enlargement perspective effects.
In general, the known mechanisms for effecting axial and angular adjustments of lens elements have not been constructed and positioned for maximum convenience of use and for precise operation. To the extent they have been included in enlargers in the past, they have been awkward and difficult to operate, or have merely offered adjustment in the axial direction. Thus, as known alignment devices have suffered wear and tear, the lens stage has become misaligned with no provision for realignment. Moreover, alignment has been a time consuming process requiring special tools not readily available. Still further, the occassional need to realign the lens stage for a different lens or in order to create special effects has exacerbated the aforenoted problems.